The hierarchy of controls, simply put, ranks methods for managing workplace hazards from most effective to least effective. From an operational health and safety standpoint, it assists employers in deciding on strategies such as hazard removal, replacement, physical control, procedural exposure management, or the provision of personal protective equipment. This hierarchy offers significant advantages to Canadian employers, especially in Alberta, British Columbia, and Saskatchewan, by enhancing hazard assessment, risk reduction, and compliance decisions.
After a hazard has been identified and its risks assessed, the hierarchy of controls is implemented. It's more than just a theoretical safety concept or a training visual. It's a device designed for decision-making.
Simply put, eliminating a hazard is more dependable than expecting perfect compliance from workers regarding rules, procedures, or gear. This is important due to the fast-paced reality of work, where situations evolve, staff are under pressure, tools deteriorate, and supervisors can't monitor everything simultaneously.
Elimination, substitution, engineering controls, administrative controls, and personal protective equipment are the standard tiers. In that sequence is how employers should consider them, keeping in mind that numerous hazards require multiple controls. Various entities like construction companies, warehouses, fabrication shops, food processors, municipalities, or service contractors may need a blend of physical safeguards, procedures, training, supervision, inspections, and PPE to effectively manage the same hazard.
To reduce exposure, controls are selected by moving through the hierarchy, starting with hazard identification. This prevents employers from making the usual oversight of prioritizing PPE simply because it's fast, obvious, and simple to provide.
As an illustration, when employees face exposure to dust in the air, distributing respirators could be a necessity, but it ought not to be the primary and exclusive remedy. The employer's initial questions should focus on dust elimination, alternative materials/processes, source control through ventilation/wet methods, and exposure time reduction. The need for respiratory protection remains, but it's integrated into a broader system instead of being the exclusive focus.
The hierarchy's usefulness is evident in this. This prompts employers to formulate superior questions to define "safe enough."
Elimination and substitution are the strongest controls because they reduce the hazard at the source.
Elimination means removing the hazard entirely. If a task creates unnecessary exposure, the employer may redesign the work so the task no longer has to happen. A simple example is storing frequently used materials at ground level so workers do not need ladders for routine picking. Another example is prefabricating components at a safer location instead of exposing workers to higher-risk work at height on site.
Substitution means replacing the hazard with something less hazardous. A company may replace a more hazardous chemical with a safer product, use electric equipment instead of fuel-powered equipment indoors, or change from a dusty material to a pelletized or pre-mixed product. The key is to assess the replacement carefully. A substitute should not introduce a new hazard that is equal to or worse than the original one.
In Alberta, BC, and Saskatchewan, this approach also supports due diligence because it shows the employer did not simply accept the hazard as unavoidable. The employer assessed whether the hazard could be removed or reduced before relying on lower-level controls.
Engineering controls are physical changes to the workplace, equipment, or process that reduce exposure. These controls are often more reliable than procedures because they do not depend as heavily on worker behaviour.
Examples include machine guards, guardrails, ventilation systems, sound barriers, traffic separation, lifting devices, interlocks, enclosures, and fixed barricades. In a warehouse, this may mean separating pedestrian walkways from forklift routes. In a shop, it may mean guarding moving parts. On a construction site, it may mean guardrails, covered walkways, or controlled access zones where overhead work is taking place.
Good engineering controls need to be designed, installed, inspected, and maintained. A guard that is removed and not replaced is no longer a control. A ventilation system that is poorly designed or not maintained may create a false sense of security. This is where inspections and preventive maintenance become part of the control system.
Administrative controls are rules, procedures, schedules, training, supervision, permits, signage, inspections, and work planning methods that help workers perform tasks safely.
They are important, but they are usually less reliable than elimination, substitution, or engineering controls because the hazard remains in the workplace. A safe work procedure can reduce risk, but only if workers understand it, supervisors enforce it, and the work conditions match the procedure. Training can improve decisions, but it does not physically remove the hazard.
Examples include rotating workers to reduce exposure time, scheduling high-risk work when fewer people are nearby, using permits for confined space or hot work, restricting access to hazardous areas, completing pre-job hazard assessments, and requiring competent supervision for higher-risk tasks.
Administrative controls work best when they are specific, realistic, and connected to the job. A generic procedure sitting in a binder does not control much. A clear procedure reinforced through orientation, toolbox talks, inspections, and supervisor follow-up is much more useful.
Personal protective equipment is still important, but it is the last line of defence. PPE includes items such as gloves, safety glasses, hard hats, hearing protection, respirators, face shields, high-visibility clothing, fall protection equipment, and protective footwear.
PPE protects the worker from exposure, but it does not remove the hazard. It can also fail if it is poorly selected, damaged, uncomfortable, improperly fitted, unavailable, or used incorrectly. Respirators need proper selection and fit testing. Hearing protection must match the noise exposure. Gloves must be suitable for the chemical, cut, heat, or puncture hazard involved.
This does not mean PPE is weak or optional. It means PPE should not be treated as the entire safety plan when higher-level controls are reasonably practicable. The strongest programs use PPE as part of a layered control strategy.
During a hazard assessment, the hierarchy should be used as a structured decision process. Once the hazard is identified, the employer should ask whether the hazard can be eliminated. If not, the next question is whether it can be substituted. If that is not reasonably practicable, the employer should consider engineering controls, then administrative controls, then personal protective equipment.
This process should be documented. In Alberta, employers are required to assess the worksite, identify existing and potential hazards, involve affected workers, and document the methods used to control or eliminate hazards. BC employers are expected to assess risk, correct unsafe conditions, and monitor controls. Saskatchewan guidance also emphasizes hazard identification, assessment, and documented risk controls.
For employers operating across Alberta, British Columbia, and Saskatchewan, the wording may differ by jurisdiction, but the practical expectation is consistent: identify hazards, select appropriate controls, communicate them, verify that they work, and update them when work changes.
Poor hazard control creates a direct business risk. If a company identifies hazards but relies mostly on reminders, generic procedures, or PPE, higher-risk exposure may continue. That can lead to injuries, work stoppages, equipment damage, rework, missed schedules, WCB claims, regulatory orders, failed COR audits, and lost client confidence.
The cause and effect are straightforward. Weak controls allow exposure to continue. Continued exposure increases the likelihood of incidents, near misses, and non-compliance findings. Those outcomes create consequences that show up as downtime, claim costs, legal exposure, strained supervision, and reduced productivity.
Measurable impact should be tracked through internal performance indicators rather than unsupported promises. A realistic employer can measure the number of high-risk hazards with only PPE listed as a control, the percentage of corrective actions closed within 30 days, the number of repeat inspection deficiencies, the number of overdue hazard assessment reviews, and the percentage of supervisors trained in hazard assessment and control selection.
A practical target might be to reduce repeat inspection deficiencies by 25 percent within six months, close 90 percent of corrective actions within 30 days, and eliminate all “PPE-only” controls for high-risk tasks unless higher-level controls have been reviewed and documented as not reasonably practicable. These are defensible targets because they can be verified through inspection records, corrective action logs, training records, and hazard assessment reviews.
Situation: A small industrial contractor was preparing for a client audit and found that many high-risk tasks listed gloves, safety glasses, and hard hats as the main controls, with little evidence that engineering or administrative controls had been considered.
Action: The company reviewed its hazard assessments, added task-specific controls, installed physical barriers in key work areas, improved traffic separation, updated procedures, trained supervisors, and created a corrective action tracker.
Result: Within three months, repeat inspection findings dropped, supervisors had clearer expectations, and the company had better evidence for client pre-qualification and audit review. The work did not become complicated. It became more controlled.
Calgary Safety Consultants helps employers build practical safety systems that connect hazard assessment to real workplace controls. This includes reviewing existing hazard assessments, improving control selection, developing safe work practices, supporting COR consulting, preparing for audits, delivering training, and helping employers close compliance gaps before they become larger problems.
For employers in Alberta, British Columbia, Saskatchewan, and across Canada, the goal is not to create paperwork for its own sake. The goal is to build a system that helps supervisors make better decisions, workers understand the controls, and management demonstrate due diligence.
If your company needs help improving hazard assessments, selecting controls, preparing for COR or SECOR, responding to inspection findings, or strengthening your safety program, visit https://calgarysafetyconsultants.ca to learn more.
The hierarchy of controls is one of the most practical tools in workplace safety because it helps employers move beyond quick fixes. When you start by asking whether the hazard can be removed, reduced, isolated, managed, or controlled through layered protection, you make better decisions. You also create a safer, more reliable, and more defensible workplace.
Sources consulted for this article include Canadian regulatory and occupational health and safety guidance from the following organizations:
Canadian Centre for Occupational Health and Safety, Hazard and Risk – Hierarchy of Controls:
https://www.ccohs.ca/oshanswers/hsprograms/hazard/hierarchy_controls.html
Canadian Centre for Occupational Health and Safety, Using Personal Protective Equipment as a Control Measure:
https://www.ccohs.ca/ppe-considerations
Government of Alberta, Occupational Health and Safety Code, Part 2 Hazard Assessment, Elimination and Control:
https://search-ohs-laws.alberta.ca/legislation/occupational-health-and-safety-code/part-2-hazard-assessment-elimination-and-control/
WorkSafeBC, Controlling Risks:
https://www.worksafebc.com/en/health-safety/create-manage/managing-risk/controlling-risks
WorkSafeBC, Basics of Risk Management:
https://www.worksafebc.com/en/resources/health-safety/information-sheets/basics-risk-management
Government of Saskatchewan, Hazard Identification and Risk Assessment Guidelines:
https://taskroom.saskatchewan.ca/health-and-safety/hazardguidelinesarticle
Government of Saskatchewan, The Occupational Health and Safety Regulations, 2020:
https://pubsaskdev.blob.core.windows.net/pubsask-prod/126367/S15-1r10.pdf
Elimination and substitution are considered the strongest controls because they deal with the hazard at the source. If the hazard can be removed or replaced with something safer, workers are not relying only on procedures, supervision, or PPE to stay safe. This usually creates a more reliable and defensible safety control.
Engineering controls are generally stronger because they physically separate workers from the hazard or reduce exposure at the source. Administrative controls, such as procedures, training, scheduling, and signage, still matter, but they depend more on worker behaviour and consistent supervision. Many workplaces need both.
Personal protective equipment is important, but it should not be the only control when higher-level controls are reasonably practicable. PPE does not remove the hazard; it protects the worker from exposure. Employers should first consider elimination, substitution, engineering controls, and administrative controls before relying mainly on PPE.
The hierarchy of controls helps employers show that they have assessed hazards and selected appropriate controls. In Alberta, British Columbia, and Saskatchewan, employers are expected to identify hazards, control risks, communicate requirements, and verify that controls are working. Using the hierarchy creates stronger evidence for inspections, audits, and due diligence.
The hierarchy improves risk reduction by helping employers choose controls that are more reliable and less dependent on perfect human behaviour. For example, a guardrail, machine guard, or ventilation system usually provides stronger protection than a warning sign alone. Better control selection can reduce repeat hazards, incidents, corrective actions, and audit findings.
Employers should document the hazard, the risk level, the controls considered, the controls selected, and the person responsible for implementation. COR auditors typically look for evidence that hazards were identified, controls were applied, workers were trained, and corrective actions were followed up. A strong hazard assessment should show more than a list of PPE.
The hierarchy of controls is a structured approach used to eliminate or reduce workplace hazards by prioritizing the most effective controls first. It starts with elimination and ends with PPE. This framework helps employers reduce reliance on worker behaviour and improve overall safety outcomes.
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Calgary Safety Consultants provides practical occupational health and safety consulting, safety training, COR support, safety program development, and regulatory compliance support for employers across Alberta, British Columbia, and Saskatchewan.
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